Screw removing tool



March 24, 1953 F. E. FETsKO 2,632,486

SCREW REMOVING TOOL Filed 001;. 9, 1951 Ill f, BY

42 9 BTTORNEYS Patented Mar. 24, 1953 UNITED STATES PATENT OFFICE 2,632,486 SCREW REMOVING TOOL Francis E.-Fetsko, Arlington; Va. Application October 9, 1951, Serial No; 250,469

. 1. Thi's inve'nti'on relates to a screw removing tool which is adaptedv to housed-most advantageously on sur-faces having" a plurality of screws therein, such as" airplane wings or fuselage sections.

Manytimes inr'emovingscrews'by the ordinary hand screw driver, screws which are difiicult to remove cause the person operatin the screw driver tolet' same slip and destroythe slot in the screw'head so that thesc'rew driver then will not engage the screw head properly. In such a case it is generally necessary touse some" special means to remov'e this screw. This" invention makes it possible to remove such screws with a minimum of effort and time.

Inview of the above, one of the objects of thisinvention is'to provide a tool for removing screws which are d'ifiicult" to remove using an ordinary hand screw driver.

Another object of this invention is the provision of a-tool having one support member anchored to the surface from which the screw; is to be removed, this anchored support member acting as the steadyin'g member for a pivotally mounted lever attached thereto which carriesthe screwdriver.

Stillanother object is the provision of a' screw removing tool having" adjustable support members so arranged that the optimumpperating angles between parts may be maintained when there is considerable curvature of the surface in which the screws are secured.

Other objects and advantages of this invention will be brought out-in the following specification and" drawings wherein:

Fig. 1 shows the general arrangement of the tooicomponents and the manner in which the tool is applied to a curved surface for removing V Fig. .2 is a vertical section through the anchor arm assembly; Fig. 3 isa horizontal section taken alongline' V mounted aboutpin-d at one extremity of lever I,

4" Claims. Cl. Mia-32 and carries at its outer end anchor trunnion: 6. A handle 8 is pivotally mounted on pin 9 atione end of lever l.

Referring to Fig; 2, the anchor arm assembly i" comprises a tubular support lu havi'ng alower U-shaped head M. Two lockingmembers 12-. are pivotally mounted between the sides of head H on pins 53 as shown in Fig.3 and are heldtini the closed position by abutment springs M'. A. rod member i5 having. tapered notched portions i5 is slidably mounted within the: tubular support iii and is held in position by the locking mem-' bers i.': which engage shoulder I! formed on rod by the notched portion H5. The outerendiof rod i5 is threadedly connected to bifurcated anchor it having spaced. hook portions l9: extending downwardly therefrom to receive an anchor member or trunniontfi-t The screw removing assembly 3 as shown in Fig. 1 comprises a tool rod 28 having circular recessed portions 21' which form a series oi ajdjusting steps. A' tool receiving" member 22 is fixed to the lower end of toolrodw'and' carries a suitable tool bit 2'4. Socket member 25 is se-' cured to the upper end of tool" rod 20 andris adapted to receive a handle member for. rotating the rod. As shown in Fig. 6,.t'oo1 rod'20 extends through slot 2 and is held. in position by alock ing means comprisinga split sleeve 26' having its inner surface shaped to conform to the stepped: portions of the rod 29' and having a lower flanged portion adapted to extend over" the lower edges of the lever I as shown. The upper end of the split sleeve 26 is threaded to receive a nut 27 which engages a flanged bushing 28 loosely fitted over the threads and in engagenient with the slotted portion of leverland: acts to hold the assembly in the" desired position.-

As shown in Fig. I, the handle 8"is pivotally mounted on pin s. and is held locked in the.extended position by means of a, locking bar'30 whichen'gages a notch 33' inthe handle 8. An operatingfpin 32. is secured to locking bartflior actuating same against the pressure of a coil spring 33. Another notch 34 is provided for mer:

ing handle 8 in the upright" position as shown bythe' dotted lines of Fig. 1

Referring to Fig. 5, anchor trunnion ecumprises an enlarged semicylindric'al portion 35' having a transverse bore 31 extending radially therethroughand support arms 36 extending from either side thereof. As shown in'Fig. 4; the ratio of the diameter ofthe semicircularportion" of trunnion 6 to the supporting arms 36 is such mat-when it isolated in the hook portions F9" of anchor member l8 the lower portion of extends below the lowest point of hook members l9. This makes it possible to secure the trunnion member 6 to a surface and introduce the hook portions [9 of the anchor arm beneath the support members 36 and allow the anchor arm to rotate freely about members 36.

In Fig. 7 there is shown a modified anchor arm which comprises a cylindrical section All having a tapered upper portion 4| and threaded bore 42 adapted to threadedly engage rod [5. A transverse notch 43 extends far enough inward to connect with an enlarged screw head receiving socket 34 which has a tapered portion shaped to conform to the screw head. A vertical slot forming the face 46 is cut to allow the anchoring screw to enter the screw head receiving socket 44. This modified anchor arm in effect takes the place of the anchor flange l8 and trunnion 3. This anchor member is especially adapted for use on flat surfaces although it could be used on other surfaces.

In use, the screw removing tool is set up as shown in Fig. 1 upon a surface 5 containing a plurality of screws which are to be removed. In the event that the workmen have trouble removing a screw, such as that shown at 3'3, the screw nearest 38 is removed and then used to secure anchor trunnion 6 to surface S. After the anchor trunnion is secured to the surface, the anchor arm assembly 4 is connected to the trunnion 6 by positioning hook-like portions l9 under arms 36 and is adjusted to the proper height by pressing inwardly on the lower portion of lock members [2 so as to disengage them from shoulder I! and thereby allow free sliding movement of rod l5 within the tubular member IS. After ascertaining the correct height, the lock members are allowed to engage the rod and hold it in the desired position.

In order to position the screw removing assembly 3, nut 21 is loosened with the aid of handle 29 so as to free bushing 23 and the lower flange of sleeve 25 from tight contact with the side portions of the slotted section of lever l. The screw removing unit is then slid along until tool bit 24 is directly over the screw 33. If after positioning the tool bit 24 over the screw 38 it is necessary to adjust the height of the unit to maintain the proper angular relationship between tool components, the nut 21 is removed, the bushing 28 is removed and the split sleeve 26 extended outwardly so that the raised portion on the inner face of the sleeve will clear the stepped portions 2| on tool rod 23. rod 2!] is free to slide within the split sleeve, the proper height may be determined and the split sleeve then engaged with the stepped portions of rod 20 and locked in position by the assembly of member 28 over the split sleeve and the tightening of same by means of nut '21.

It is very important that the proper angular relationship of the tool components be maintained for best results. Obviously the most desirable relationship of the components will be such that the force applied by the lever will cause the screw removing assembly 3 to exert a turning movement having a downward component of force directed along a line coincident with the central vertical axis of the screw.

After setting up the tool as mentioned above, the handle 8 is placed in a horizontal position as shown and force is applied downwardly at this point while the tool bit 24 is rotated by means of a handle which is adapted to be re- When the 4 ceived by socket member 25 and thus the screw 38 is removed.

From the description of the tool in use it will appear that the most favorable position of the screw removing unit with respect to the remainder of the tool can be obtained on either a curved or flat surface by virtue of the adjustable height of the screw removing assembly 3 and the anchor arm assembly 4 as well as the rotatability of the anchor arm about the anchor trunnion 6. These three adjustable features when combined with the slidable mounting of the screw removing assembly 3 make it possible to maintain the proper working angle and direction of force regardless of the type of surface being worked upon.

The success of operation of this tool does not depend upon the multiplication of forces by means of levers but rather on the maintaining of the tool components in such a relationship that the force applied by the screw removing assembly 3 is directed downwardly in a line coincident with the central vertical axis of the screw. When the force is thus directed and the tool bit held firmly in position screw removing is easy and rapid.

The details of construction of the particular embodiment of the invention herein illustrated and described are not to be taken as limiting the scope of the invention since the device may be constructed in many forms.

What I claim is novel and desire to secure by Letters Patent of the United States is:

1. A screw removing tool adapted to remove screws from surfaces which may be flat, curved, or irregular, comprising a slotted lever, a pivotally mounted anchor arm carried by said lever, the anchor arm being bifurcated to provide hook portions on the lower end, an anchor member adapted to be secured to the surface from which the screws are to be removed, said anchor member comprising a semicylindrical portion having a bore transversely extending therethrough adapted to receive an anchoring screw and a support arm extending from each end thereof,

said arms being rotatably engaged by the anchor arm hook portions, and a screw removing assembly slidably carried in the slotted portion of the aforementioned lever.

2. A screw removing tool adapted to remove screws from surfaces which may be either flat, curved, or irregular, comprising a slotted lever, a tubular support pivotally carried by said lever, said support having a lower U-shaped head por- 131011, a pair of spring biased locking members supported within said U-shaped head portion, a notched rod slidable in the tubular support and held in locked position by aforesaid looking members, an anchor arm secured to the notched rod, said anchor arm having depending hook portions, an anchor trunnion having a bore extending therethrough adapted to receive an anchoring screw pivotally engaged by the aforementioned hook portions to serve as the means for anchoring the tool to a given surface, a screw removing assembly slidably positioned in the slotted portion of said lever, said screw removing assembly including a notched screw head engaging member, a pair of split sleeves adapted to interfit with the notched portion of said engaging member, and means for holding said split sleeves in contact with said engaging member and securing said engaging member with respect to the slotted lever section,.and a handle pivotally mounted on the end portionvoi said lever opposite to that 01 the aforesaidtubular support.

3. The tool as described in claim 2 wherein the anchorftrunnion comprises a semicylindrical portion having a bore radially extendingftherethrough, and a support arm extending from each side of said semicylindrical memben' the support arms being rotatably engaged by the hook portions of the anchor arm.

6 REFERENCES crrnn file of this patent:

4. The tool as described in claim 1 wherein 10 the semicylindrical center portion of the anchor member has a diameter greater than that of the supporting arms so that upon engagement of the hook portions of the anchor arm withthe support arms the hook portions will not"v bear 16 against the surface to which the trunnion is anchored.

FRANCIS E FE'I'SKO.

5 UNITED STATES PATENTS Number Name Date 1,131,777 Gage Mar. 16, 1915 1,331,824 Powers Feb. 24, 1920 1,540,749 Beach June 9, 1925 FOREIGN PATEfi'Ts j Number Country 5 Date 8,127 Great Britain 1909 228,362 Germany Nov. 8, 1910 423,690 France Feb. 22, 1911 391,124 Great Britain Apr. 18, 1933 

